Semiconductor integrated circuit (IC) technology has experienced rapid progress including the continued minimization of feature sizes and the maximization of packing density. The minimization of feature size relies on improvement in photolithography and its ability to print smaller features or critical dimensions (CD). Various techniques have been developed to enhance the resolution of optical lithography. An example of such a technique is off-axis illumination (OAI). OAI illumination may include any radiation that reduces and/or eliminates the “on-axis” (on the optical axis) component of the radiation. For OAI however, the shape and size of the illumination must be optimized for the specific pattern that is to be printed on a substrate. Another RET technique used is double dipole lithography (DDL) or double patterning which can use a strong OAI. DDL requires decomposition of patterns into a vertical pattern and a horizontal pattern, which in turn requires two (double) exposure processes. However, the process window to perform DDL may be limited. Therefore, improvement of one or more of these disadvantages is needed.